Britain is failing to board and seize Russian 'shadow fleet' ships in the English Channel over fears about the cost of storing the vessels and asylum claims from the crew, it emerged today.

Sir Keir Starmer has given approval for Britain's commandos to board and halt the sanction-breaking ships as they pass through UK waters. 

But none have so far been boarded, despite several using the busy waterway since he gave them the green light last month.

Home Secretary Shabana Mahmood and Foreign Secretary Yvette Cooper have raised concerns about asylum claims by Russian mercenaries crewing the ships.

And fears have been voiced about the cost of mooring the seized vessels, with officials citing the cost to the Irish government of holding the drug-running ship MV Matthew.

The Panama-registered vessel was confiscated in September 2023 after it was boarded and 2.2 tonnes of cocaine worth 157 million euro (£132 million) was found in the hold.

But it has cost 14 million euros (£12million) to maintain since then in Cork Harbour.

Earlier this month Sir Keir was criticised after the Royal Navy allowed a Russian warship to escort two shadow fleet vessels past Dover.  

The frigate Admiral Grigorovich passed the coast with the 'senior service' only able to rustle up a support ship to watch them head for the Black Sea.

RFA Tideforce, an auxiliary tanker armed with only light defensive weapons, simply followed the three-ship flotilla past Dover without intervening.

Moscow's shadow fleet is reported to be made up of more than a thousand ageing tankers.

They illicitly ship oil and other goods out of Russia by flying the flags of other countries, with the aim of evading sanctions imposed by the West since the invasion of Ukraine began.

JEF countries Finland, Sweden and Estonia have recently intercepted suspected shadow tankers travelling through the Baltic.

Announcing his plan to allow commando raids, Sir Keir said in March:  '(Russian President Vladimir) Putin is rubbing his hands at the war in the Middle East because he thinks higher oil prices will let him line his pockets.

'That's why we're going after his shadow fleet even harder, not just keeping Britain safe but starving Putin's war machine of the dirty profits that fund his barbaric campaign in Ukraine.

'He and his cronies should be in no doubt, we will always defend our sovereignty and stand with Ukraine for as long as it takes.'

Defence Minister Luke Pollard has said the fact a Russian warship escorting shadow fleet tankers 'shows how vulnerable they now are'.